Mechanism for projecting and retracting aircraft lift rotors



Sept. '13, 1949. G. G, DOWNlNG 2,481,502 MECHANISM FOR PROJECTING AND RETRACTING AIRCRAFT LIFT ROTORS 7 Filed July 27, 1943 4 Sheets-Sheet 1 Fig. 3

' K INVENTOR.

w mz%owz yi Sept. 13, 1949. G. e. DOWNING 2,431,502

' MECHANISM FOR PROJECTING AND RETRACTING AIRCRAFT LIFT ROTORS I Filed July 27, 1945 4 Sheets-Sheet 2 Fig.5

Fig. 4

BY f

INVENTOR.

W a a Q9 Sept 13, 1949. e; a. DO-WNING 2,481,502

' MECHANISM FOR PRQJECTING AND RETRACTING AIRCRAFT LIFT ROTORS Filed July 27, 1943 4 Shee ts-Sheet 3 Sept. 13, 1949. DOWNING 2,481,502

MECHANISM FOR PROJECTING AND RETRACTING AIRCRAFT LIFT ROTORS Filed July 27, 1945 4 Sheets-Sheet 4 9* BY F607 2 FEE owacji Patented Sept. 13 1949 UNITED STATES ATE-NT OFFICE MECHANISM FOR PROJECTING AND BE- TRACTING AIRCRAFT LIFT ROTORS George G. Downing, Atlanta, Ga.

Application July 27, 1943, Serial No. 496,283

3 Claims. 1 p This invention relates to a flying machine, airplane or high speed rotor-plane and more particL- larly to a machine of this character which embodies a high wing and a rotor.

The objects of this invention are to provide improvements in an airplane of this type which combines the high flying speed of a wing plane with the low take-off and landing speed of a rotorplane. 1

With this end in view this invention consists generally in mountin the pylon strut of the rotor on a vertically movable carriage which is guided on rods forming part of the frame structure of the plane, a fluid actuated motor whereby said carriage may be raised and lowered for raising the rotor into an operative position or lowering the same into an inoperative position within a well in the wing, means for locking the mechanism in its extended position, means for braking the rotation of the rotor and locking the same against rotation preparatory to stowing the same in the well of the wing, and means for releasing the rotor and associated parts and permitting of jettisonin the in case of emergency.

In the accompanying drawings:

Fig. 1 is a diagrammatic top plan view of a flying machine embodying this invention.

Fig. 2 is a front elevation of the same.

Fig. 3 is a side elevation thereof.

Fig.4 is a fragmentary front elevation, on an enlarged scale, of the rotor and the mechanism associated therewith while the rotor is lowered into' an inoperative position within a Well in the wing, this view being taken substantially on line 4 3 Fig. 1.

Fig. 5' is a side elevation of the same but showing the mechanism in a position in which the rotor, pylon strutand'associated parts are raised.

Fig. 6 is a horizontal section, on a still larger scale, taken on line 6-6, Fig. 4, looking downwardly. a

Fig. 7 is a fragmentary vertical section, on an enlarged scale, taken on line Fig. l, showing the carriage for supporting the rotor and asso-- ciated parts in a lowered position.

Fig. 8 is a similar view taken on line 8-8, Fig. i, but showingthe carriage for supporting the rotor and associated parts in an elevated position.

Fig. 9 is a fragmentary side elevation of the releasing means whereby the rotor and associated parts may be jettisoned when desired.

- Inthe following description similar reference characters indicate like parts in the several figures of, the drawings.

Although this invention may be embodied in flying machines or airplanes of various types and constructions, the same is more particularly adapted for use in connection with a high-wing monoplane, which is shown in the drawings and of which the essential parts are organized as follows:

The numeral 33 represents the fuselage or body of the airplane which may have the form, of a longitudinal horizontalcylinder, as shown in Figs. 1-4. On opposite sides of the fuselage are arranged longitudinal booms 34, 34 and each of these is provided at its rear end with a lateral steering rudder 35. Transversely over the central part of the fuselage and the front ends of the booms is arranged a high wing l which may be connected with the fuselage and booms in any suit.- able manner. Between the rear ends of the booms is arranged a stabilizer or elevator 36. The latter and the rudders may be operated in any well known manner.

On the front end of the fuselage is rotatably mounted a front driving propeller El and On the rear end of the same is rotatably mounteda rear drivin propeller 38, which propellers turn about a horizontal axis extending lengthwise of the fuselage and may be driven in any suitable manner by means of power plants, such as gas engines, mounted in the fuselage, for driving the airplane forwardly. Landing wheels 39 are adapted to be lowered from the fuselage and booms when making a landing.

The numeral 2 represents a rotor which is arranged above the wing, the fuselage and booms and adapted to rotate about a vertical axis and provide for additional lift for takecif or landing. In

its preferred form this rotor comprises two blades which project from diametrically opposite sides of a hub 29 so that they are in line with each other. Operating means are provided for raising and lowering this rotor into and out of its operative position, also housing or storing the same in the wing when lowered,.also driving the same, also locking the same in its elevated position, also braking the rotation of the same, also looking the same in a predetermined position relative to the wing preparatory to stowing the rotor in the Wing, and also to jettison the same when desired, which means embody the present invention and are preferably constructed as follows:

The numeral 3 represents an upright upper driven shaft, to the upper end of which the hub 48 of the rotor is secured and which is adapted to rotate about its vertical axis when in use and also is capable of moving upwardly for bringing the rotor into its operative position and lowered for bringing the rotor into its inoperative position. When in its lowered position the blades of the rotor are arranged crosswise of the fuselage and are dropped into a well or pocket 4| formed lengthwise in the upper side of the wing. This well is of such depth that when the rotor is within this well the top of the rotor does not project above the wing, thereby enabling the wing to perform its f unctionwithout interference from the rotor.

The upper driven shaft 3 is arranged within a tubular pylon strut, mast, post or standard 25 which is mounted at its lower end on a vertically movable carriage so as to be compelled to rise and fall therewith, and is also connected with said carriage by locking means which permit the rotor and associated parts to be detached from the carriage.

Although this carriage may be variously constructed the same comprises a central upright housing tube 4 arranged below the pylon strut 25 and axially in line therewith and upper and lower spiders I9 and 43 connected with the upper and lower ends of the housing tube. This carriage is guided in its vertical movement by means of upright guide sleeves 44 connected with the upper and lower spiders and sliding vertically on upright guide rods 5 which are connected at their upper and lower ends with the frame structure of the fuselage in any desired manner.

The preferred means for detachably connecting the pylon strut and associated parts with the carriage are constructed as follows:

The numeral 21 represents a coupling ring or flange which is connected with or practically forms part of the lower end of the pylon strut and-'which'normally rests on the upper side of the upper spider H), as shown in Fig. 8. The

lower end of the upper driven shaft 3 is arranged within the coupling ring 21 and is rotatably coupled therewith by an annular bearing which 7 includes balls 26 running with their outer and same to move vertically therewith.

The carriage and the coupling ring 21 are detachably connected by a locking device which is constructed as follows:

Adjacent to the outer edge of the coupling ring 21 one or more locking pawls or dogs are arranged, each of these pawls being pivoted by a horizontal pin 4'1 on the adjacent part of the upper spider and provided with an inner jaw 28 which is adapted to bear against the upper side of the coupling ring 21 and also having an outer arm 48 preferably formed integrally therewith and carrying a pivoted roller 32. Below the arms of the several pawls and rotatable concentrically about the axis of the coupling ring, pylon strut and upper driven shaft 3 a cam ring 30 is arranged and supported on the adjacent part of the upper spider by an annular bearing consisting preferably of bearing balls 3| interposed between raceways 49, 50 on the cam ring and the upper spider. On its upper side the cam ring is provided with upwardly projecting cams 5|, each of which, upon turning the cam ring in one direction, engages the roller 32 of one of the coupling pawls and moves the same upwardly, as shown in Fig. 9, and thereby moves the jaw 28 on the inner end of this pawl downwardly into engagement with the upper side of the coupling ring 21, as shown in Fig. 8, whereby the pylon strut .is connected with the. vertically movable 4 carriage. The cam ring is maintained in this position during the normal operation of the airplane by means of a manually releasable detent device which preferably comprises a locking bolt 29 slidable radially in a guideway 52 on the upper spider IQ of the carriage and yieldingly held with its outer end in engagement with a locking recess 53, on the inner side of the cam ring, by a spring 54 interposed between companion shoulders on the outer end of this bolt and the inner end of said guideway, as shown in Fig. 8. Outward movement of the locking bolt on the upper spider the inner jaws 28 of the coupling pawls out of the V path of the coupling ring and thus cause the rotor, pylon strut and associated parts to be jettisoned from the airplane. The withdrawal of the locking bolt from the cam ring for this purpose can be accomplished in any suitable manner, for

example by a line connected'with the inner end of 7 this bolt and leading to the cockpit within convenient reach of the aviator so that the latter can 7 effect the release and jettisoning of the rotor, V

pylon strut and associated parts manually whenever desired or an emergency requires this operation.

Shifting means are provided, which embody the present invention, for raising and lowering the rotor and associated parts, which means preferably have the form of a hydraulic motor and are constructed as follows:

The numeral 1 represents an upright rigid post or column provided at its lower end with a fixed base 51 which is mounted on any available part of the frame structure of the airplane. At its upper end this post is provided with a stationary lifting or motor piston 9 which engages with the bore of a vertically sliding lifting or floating motor cylinder 8 surrounding the post I. This cylinder is provided at its upper end with a head 58 thereby forming a lifting pressure chamber 98 between this piston 8 and the cylinder and its head 58 into which a hydraulic pressure fluid, preferably oil or other liquid, is forced for raising this cylinder and the parts carried thereby and from which this fluid is also exhausted for loweringthe same. The preferred means employed for introducing and withdrawing the pressure liquid from this pressure chamber include a rigid upright tube or pipe 6 mounted within the post I and opening at its upper end into the pressure chamber and provided at its lower end with a tube 59 which is connected in any suitable manner with pumping means whereby liquid may be forced into the pressure chamber 98 and also withdrawn therefrom. Likewise any suitable valve means may be employed for controlling admission into and dischargin the pressure liquid from the pressure chamber 98 for raising and lowering this cylinder as required. Y r

V, The upward movement of the carriage is limited by stopmeans which may be of any suitable construction but preferably consist of a stop l5 projecting upwardly I from the upper carriage spider l9 and adapted to engage with an abutment or fixed'stop l6 mounted on the adjacent part of the, frame structure, of the fuselagaas shown in Fig. 8.. After the carriage and the parts mounted thereon have been raised into this position the same are held there by a detent or retaining device which is, preferably-constructed as follow; r

The numeral represents a retaining or detent arm which is pivoted at its upper end by a pin H on a. stationary part of the frame structure of the fuselage adjacent to the path of the carriage and provided at its lower end with a retaining roller I18. This arm is moved horizontally toward and from the upper carriage spider by a piston l! which is connected with the retaining arm and slidable in a cylinder l2 adapted to receivefluid under pressure. When the carriage has been raised to the position in which its stop engages with the frame stop 56, then pressure fluid is ad= mitted into the cylinder '52 whereby the retaining arm 1-0 is moved inwardly and the roller I8 engaged with the underside of the spider l9, as shown in full lines in Fig 8, thereby holdingthe carriage in its elevated position together withthe parts mounted thereon. The fluid pressure may be supplied to and withdrawn from this cylinder by any suitable means and the control of this pressure fluid may also be eifected by any suitable valve means under the control of the aviator. When it is desired to lower the carriage the pressure fluid is withdrawn from the cylinder 12 whereby the roller I8 is disengaged from the underside of the spider I9.

The vertical movement of the lifting cylinder 8 is transmitted to the rotor, pylon strut and associated parts by means which also serve to turn the T35 rotor and which include a lower tubular driving shaft H3 arranged concentrically between the lifting cylinder 8 and the tubular housing 4 of the carriage. This driving shaft is mounted on the lifting cylinder and the carriage so as to be com:- pelled to move vertically therewith but is free to turn relative to this cylinder and the carriage. The preferred means for accomplishing this purpose oonsists in journaling the lower and upper ends of the lower driving shaft H3 by ball bearings l l and tion the lower and upper ends of the lifting cylinder and similarly journaling the lower and upper ends of this lower driving shaft by ball. bearings l3 and M on the corresponding ends of the carriage tube 4. ing s is of the usual type in which an annular row of balls is interposed between channel-shaped raceways mounted on the respective members to permit one of them to rotate relative to the other but prevent relative longitudinal movement of these members, as shown in Figs. 7 and 8.

Coupling means are provided whereby the upper end of the lower driving shaft I0 and the lower end of the upper driven shaft 3 of the rotor are normally connected but permit of quickly disconnecting the same when'it is desired to jettison the rotor and associated parts in case of an emergency. These coupling means preferably comprise an upwardly tapering conical shank arranged at the upper end of the lower driving shaft l0 and engaging with a downwardly tapering socket Bl in the lower end of the upper driven shaft 3 and-one or more keys 82 arranged lengthwise on the periphery of the conical shank and each engaging with a longitudinal key groove 63 in the-bore of said socket, as shown in Fig. 8. By these means a connection between the lower driv ing shaft l9 and the upper driven shaft 3 is provided for positively transmitting motion from the lower driving shaft to the upper driven shaft Each of these ball bear- 5 6 but permitting them to be readily separated from each other by an upward pull of the rotor when it becomes necessary to jettison the rotor and associated parts while the airplane is in flight.

A brake device is provided whereby the rotation of the rotoris retarded preparatory to lower-i ing the rotor, and locating or centering means are also provided whereby the rotor may be locked against turning when its blades are in line with the well in the plane wing and therefore in a position to be lowered into the same when the rotor is not required.

The locating or centering means for accome plishing the above purpose comprise parts-which interlock the coupling ring 21 with the upper spider of the carriage and also parts which interlock this coupling ring and pylon strut with the upper driven shaft 3. Those parts of the locating or centering means which couple the ring 2'1 and the upper spider 29 may consist of a vertical loeating pin 88 projecting downwardly from the coupling ring and movable into and out of engagement with a locating opening 88 in this spider, as shown in Fig. 8, and those parts which interlock the coupling ring and the plyon strut and; the upper driven shaft 3 include a horizontal locating or centering bolt 82 mounted on the lower end of the pylon strut adjacent to the coupling ring and movable at its inner end into and out of engagement with a locating recess iii in the perlphery of the upper driven shaft 3. The horizontal centering bolt 82 is provided at its outer end with a cylindrical pressure chamber 83 which slidingly. receives the inner end of a relatively stationary fluid pipe by means of which a pressure fluid is supplied to this pressure chamber and withdrawn therefrom. This fiuid pipe. 84 may be connected by any suitable flexible and rupturable means with a pumping device whereby fluid may be forced into the pressure chamber 83 and withdrawn therefrom and the flow of fluid to and from this pipe may be controlled by any suit.- able form of valve mechanism which may be actuated by the aviator in the cockpit of the airplane.

The locating bolt 82 is capable of sliding axially within the bore of a tubular brake or guide sleeve 85 which in turn is capable of sliding radially toward and from the upper driven shaft 3 in a guideway 86 on'the adjacent part of the coupling ring 21 or the pylon strut. At its inner end the sleeve 85 is provided with a brake shoe 24- which is adapted to be pressed inwardly against the periphery of the upper driven shaft 3 which serves as a brake drum for retarding and arresting the rotation of the same and the rotor andassociated parts, and this brake is also movable outwardly for relieving the upper driven shaft 3 of this braking effect. Between a shoulder on the inner part of the brake guide sleeve and a shoulder on the locating bolt 82 is arranged a heavy spring 23 and between a shoulder on the outer end of the brake sleeve 85 and the outer end of the guideway 86 is arranged a light spring 22. When the rotor is elevated into its operative position the centering or locating bolt 82 and the brake shoe 24 are withdrawn out of engagement with the upper driven shaft 3 and thus leave the rotor and associated parts free to turn for takeoff and landing of the airplane. In the retracted position of the brake shoe 24 and locating bolt 82 the light spring 2'2 moves the brake shoe away from the upper driven shaft 3 and the heavy spring 23 moves the centering bolt 82 outwardly until its outer end engages a stop 81 on the brake sleeve and its inner end is drawn 23 causing the locating bolt and the brake shoe to move in unison while the light spring 22 is compressed. The inward movement of the brake shoe is arrested when thesame bears against the periphery of the upper driven shaft 3 at which time the pressure of the brake shoe against this shaft is sufiiciently highto produce a retarding effect on the rotation of the rotor. When the rotation of the rotor has almost ceased the aviator causes additional hydraulic fluid under increased pressure to flow into the pressure chamber 83 whereby the resistance of the heavy spring 23 will be overcome and the locating bolt 82 will be projected beyond the inner end of the brake shoe and into the locating recess 2! of the upper driven shaft 3 the instant this recess presents itself to this locating bolt during the rotation of the upperdriven shaft 3. and associated parts. When this occurs the rotor will be arrested in a positionin which its blades are in vertical alinement with the well in the wing and thus permits the rotor to be lowered into this well by withdrawing the pressure fluid from the pressure chamber 98 between the piston 9 and the lifting cylinder 8.

Various means may be employed for turning the rotor and associated parts but it is preferable to employ for this purpose driving means which,

areinoperative while the rotor is depressed and operative for rotating the rotor when the latter is elevated. As shown in Figs. 4, 5 and 7 these driving means may include a bevel driven wheel connected with the lower end of the lower driving shaft I I], as shown in Figs. 4, 5 and 7, a driving bevel wheel I00 arranged above the driven bevel wheel and a power. shaft l0! carrying said driving bevel wheel and journaled on any part of the frame structure.

While the carriage supporting the rotor and associated parts is in its lowered position the driven bevel wheel 2!) is out of engagement with the driving bevel wheel I00, so that no motion is transmitted to the rotor and associated parts and the same remain at rest while in a lowered position. When, however, the carriage is elevated for lifting the rotor out of the well in 'the wing and into its highest or operative position, then the driven bevel wheel 29 is engaged with the driving bevel wheel Hill, as shown in Fig. 5, whereby motion may be transmitted from the power shaft [0| to the lower driving shaft 'ID for rotating the rotor by coupling or closing a clutch which operatively connects the power shaft with the motor from which power is derived.

,The sequence of operations of this apparatus is as follows:

Let it be assumed that the airplane'is at rest on the ground and that the rotor is stored in the well of the wing. Preparatory to a takeoff the engines are started for turning the'driving propellers 31, 38 and the power shaft I [H through a-clutchand the aviator operates the valve means which admit pressure fluid into the pressure chamber 98 between the lifting piston 9 and cylinder 8, whereby the rotor is lifted together with the carriage and parts connected therewith. "The upward movement of these parts is arrested when the stop l5 of the carriage engages the-stop 16 on the'frame structure, as shown inFig.:8, and when this occurs these parts: are locked in this position by moving the retaining arm 10 inwardly so that its roller 18 engages with the underside of the upper spider I9, as shown inFig. 8.

The rotor may be elevated and the driven bevel wheel 20 engagedwith the driving bevel wheel H10 while the clutch between the powershaft and its motor is uncoupledthus permitting the rotor to be rotated or its rotation may be arrested while the same is elevated or extended to suitreq'uire ments. e After the airplane is in] flight the retaining roller 10 is withdrawn from underneath the .car-

latter in position to permit of stowing the same in the wing well.

When it is desired to make a landing the above describedme'thod of operating the rotor and-associated parts and the lifting and driving means are effected and thereby enable-a landing to be made safely at comparatively slow speed;

If an emergency shouldarise while theairplane is in flight and the rotor is elevated; as when unexpectedly attacked or when in combat, and it becomes desirable or necessary -to. get away quickly, this can be done by retracting the locking bolt 29 which permits the spring 56 to shift the cam ring 30in the direction which releases the jaws 28 of the retaining pawls from the coupl g r g 27 and thus'causes the upward pull of the rotor to'deta-ch the upper driven shaft 3 from the lower driving shaft l0 on'the carriage. When this occurs the rotor and associated parts are jettisoned and the airplane enabled to increase its speed and make its escape from thedanger zone.

While the invention has been shown and-described in a preferred form with hydraulic'con ,trols, it is to be understood that it is not to be limited to the specific construction herein shown but that it may be practiced with electrical, me?- chanical' or pneumatic controls without departing from the spirit thereof. I

Iclaim-asmyinventionzr r 1. A flying machine comprising a frame structure, a carriage movable vertically relative to said frame structureqand having a cen tral vertical housing tube and spiders at the. upper and lower ends of said housing tube, means for guiding said carriage on said frame structure including upright guide rods mounted on said frame structure and guide tubes connected with said spiders and slidable on said rods, a motor piston mounted Unsaid frame structure, a motor cylinder sliding on said piston, means forintrod-ucing a pressure fluid into the chamber between said piston and cylinder and withdrawing thesame therefrom for raising and-lowering said cylin der, a tubularv shaft arranged between said hous-' ing tube and motor cylinder and capable of turning independently thereof but compelled to move vertically, therewith, bearings interposed be- .tween the shaft and said housing, tube and motor *2"? cylinder, and a rotor operatively connected with said shaft.

2. A flying machine comprising a frame, a carriage movable vertically on said frame and having a tubular housing, means for guiding said tubular housing on said frame, a relatively stationary motor piston mounted on said frame, a motor cylinder which surrounds said piston and is slidable lengthwise thereon, means for introducing a pressure medium into and withdrawing the same from between said cylinder and piston, a tubular shaft arranged between said housing and motor cylinder and capable of turning independently of said housing and cylinder but compelled to move vertically therewith, and a rotor operatively connected with said shaft.

3. A flying machine comprising a main frame, a carriage movable vertically on said frame and provided with a supporting ring, a vertical tubular strut resting on said carriage and provided with an external flange, a driving shaft journaled on said carriage, a driven shaft journaled in said strut, cooperating coupling means arranged respectively on said driving and driven shafts operatively connecting and disconnecting said shafts by sliding the same one relative to the other, a rotor connected with said driven shaft, and means for coupling and uncoupling said ring and flange including pawls pivoted on said car- 10 riage and each haVing an inner jaw adapted to overhang said flange and an outer operating arm, and detent means for holding said pawls either in their operative or in their inoperative position including a cam ring mounted on said carriage and engaging the outer arms of said pawls.

GEORGE G. DOWNING.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,672,163 Krammer June 5, 1928 1,732,758 Luton Oct. 22, 1929 1,793,651 Thorsen Feb. 24, 1931 1,904,923 MacCaskie Mar. 18, 1933 2,008,843 Smith July 23, 1935 2,094,105 Myers Sept. 28, 1937 2,198,941 Jacobs Mar. 30, 1940 2,229,657 Larason Jan. 28, 1941 2,330,803 Andrews Oct. 5, 1943 2,432,933 Peterson Dec. 16, 1947 2,432,941 Scott Dec. 16, 1947 FOREIGN PATENTS Number Country Date 499,632 Great Britain Jan. 26, 1939 

